<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
<script type="text/javascript" src="../script/jquery-1.7.2.js"></script>
<script type="text/javascript">

	$(function(){

	    var arr=[123,"abc",true];
		var $button = $("button");
		for (var i=0;i<$button.length;i++){
		    alert($button[i]);
		}
		alert("1");
	});

</script>
</head>
<body>

	<button id="btn">Button</button>
	<button >Button</button>
	<button >Button</button>

</body>
</html>